Technical Field
The present invention relates to an inductive detection type rotary encoder that measures a rotation angle on the basis of magnetic flux coupling between wirings provided in a rotor and a stator.
Related Art
Inductive detection type rotary encoders include a stator and a rotor: the stator has a transmission winding and a reception winding, and the rotor has a magnetic flux coupling body. In an inductive detection type rotary encoder, a transmission current flows through the transmission winding while altering its flowing direction periodically. The transmission current that flows through the transmission winding generates a magnetic field. Then, the magnetic flux coupling body generates an inductive current on the basis of this magnetic field. In turn, the reception winding detects an inductive voltage on the basis of the magnetic field generated from the inductive current flowing through the magnetic flux coupling body.
To give some examples, JP 2006-322927 A discloses an inductive detection type rotary encoder that has a stator in which a plurality of transmission windings and a plurality of reception windings are stacked with an insulating layer therebetween. In addition, the inductive detection type rotary encoder has a rotor in which a plurality of magnetic flux coupling bodies are stacked with an insulating layer.
JP 2006-322927 A discloses an absolute type encoder that has two tracks, each of which includes a transmission winding, a reception winding, and a magnetic flux coupling body; the tracks are disposed concentrically with each other.
JP 2013-152163 A discloses a compact inductive detection type rotary encoder in which a plurality of transmission windings, a plurality of reception windings, and a plurality of magnetic flux coupling bodies are stacked.
JP 4869769 B1 discloses an inductive detection type rotary encoder that has two tracks disposed concentrically with each other. Each track has a combination of a transmission winding and a reception winding provided in a stator and a magnetic flux coupling body provided in a rotor. The two tracks are disposed side by side in a direction that is orthogonal to a rotation axis, or in a radiation direction. JP 5540308 B1 discloses an inductive detection type rotary encoder that has four tracks disposed side by side in a radiation direction while being concentric with each other.